Dan Knauss of New Local Media wrote up a nice comparison between Word Press, Joomla, and Drupal last summer, which I came across last weekend. I dropped him a line with some updates based on my experiences, and he responded in a blog post: More followup on CMS comparison and notes on the Joomla extension market. Thought I'd respond here.
Thanks for continuing the discussion!
To answer your question about Ubercart, we are setting up exactly that--subscription access to content. And just having a "beta" label means little in either the Drupal or Joomla add-on world--there are plenty of solid add-ons that have been "beta" for years.
With a little help, you can get up to speed on Joomla pretty quickly, and once you've had that basic intro (understanding categories/sections/static content and what different types of add-ons do) I'd agree that a less technical person can get further. We do recommend Joomla for sites with modest needs.
Drupal, in contrast, takes more to get going, has a much steeper learning curve, but the payoff is much better integration. You don't need to link it to a separate application running as a component--often all you need is a custom content type with a view that shows what you want.
Joomla, from a developer point of view, made some huge strides in 1.5. But Drupal seems to have a more cohesive developer community, with much more consistent (and enforced) coding standards.
I really do like Joomla, but find we're doing much more Drupal these days, just because the path to a really sophisticated web site is much straighter with Drupal. And we're doing a lot more big complicated web sites these days than the basic sites that are a good fit for Joomla.